1. Field of the Invention
This invention relates, in general, to hand-held cutting tools, and in particular, to a hand-held safety holder which incorporates a conventional, single-edge razor blade, which is adapted for cutting a thin, elongated member such as a sheet or strand and to prevent the accidental cutting of the hand or other articles.
2. Summary of the Prior Art
Hand-held knives find wide application in a disparate variety of fields. A wide variety of knives having specialized purposes have been developed as a result, ranging from the scalpel of the surgeon to the double-edged knife of the oyster-shucker. In a smaller, but equally disparate, group of fields, there is a recognized need for a hand-held knife capable of cutting a strand, e.g., string, rope, fishing line, etc., or a thin sheet, such as a roll of paper, a sheet of film, or a strap.
Typical users include: Personnel engaged in preparation of articles for shipping, who need quickly to cut strapping tape or twine, packaging film or paper; workers in film laboratories engaged in loading, unloading or processing bulk quantities of photographic film; and, rescue workers engaged in extracting occupants of vehicles equipped with safety belts during emergency conditions, such as may occur at racing events, who typically cut the belts with a knife in preference to attempting to operate the buckles of the belts, which may have been rendered inoperative by the crash.
These, and other, widespread applications signal the need for a simple, reliable, inexpensive, hand-held knife which may be carried safely upon the person in the pocket or on a lanyard from the wrist or belt, which is adapted for the cutting of a sheet or strand without the danger of the accidental cutting of the user or other object.
An effect in this direction is the "Knife Handle" of Rollband, et al., found in U.S. Pat. No. 4,242,795. The handle of that invention incorporates a retractable, proprietary, single-edge blade which is actuated by a thumb-button extending through a slot in the top. A slot on the lower edge of the handle permits edgewise cutting contact between a strand or sheet and the cutting edge of the blade, whether the blade is retracted or not, while preventing the cutting contact of the blade with the hand, at least when the blade is retracted.
However, this knife is not well adapted to cutting thicker materials because of the narrow width of the slot, and tends to bind with stiffer materials, particularly stiff sheets, such as poster board and the like, because the depth of the slot and the width of the body are such as to bind with the parted halves of the material being cut before its engagement with the blade, which tends to tear or rip the material, rather than cut it. Further, the knife handle of Rollband, et al., is relatively complicated mechanically, and hence, relatively expensive.